Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target

• Milandip Karak,
• Cian R. Cloonan,
• Brad R. Baker,
• Rachel V. K. Cochrane and
• Stephen A. Cochrane

Beilstein J. Org. Chem. 2024, 20, 220–227, doi:10.3762/bjoc.20.22

• -anomers of compound 5. It is noteworthy to mention that the benzyl ether in compound 4 exhibited successful cleavage upon treatment with sodium bromate/sodium dithionite in ethyl acetate/water, while other protecting functionalities like acetyl and phenylsulfonylethyl ester groups remained intact [45

A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• . Subsequent reduction with sodium dithionite then afforded triamine 9. Another way comprised the installation of a nitroso group in compound 6 through reaction with in situ-generated nitrous acid giving nitroso compound 8. The subsequent reduction to the corresponding amine with hydrogen sulfide afforded the

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• characteristic properties, such as the biological redox cycle. The main and most common menadione reduction product is menadiol or vitamin K4, followed by its dialkyl ether and diacyl derivatives. Menadione can be easily converted to menadiol (14) by reduction with sodium dithionite, as first described by Fieser

• widely used with some adaptations. In 2003, Ito and co-workers also used sodium dithionite to obtain menadiol (14) from 10. However, in this case, the authors mixed menadione (10) and sodium hydrosulfite in acetic acid and water to obtain 14 in 97% yield [112]. More recently, still using sodium

• dithionite, Suhara and co-workers reported in their various works on the synthesis of vitamin K analogues, the use of menadione (10) to obtain 14 [113][114][115][116][117]. In these works, menadione (10) was reduced by using an aqueous 10% sodium dithionite solution in diethyl ether to furnish alcohol 14 in

Synthesis of (Z)-3-[amino(phenyl)methylidene]-1,3-dihydro-2H-indol-2-ones using an Eschenmoser coupling reaction

• Lukáš Marek,
• Lukáš Kolman,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2021, 17, 527–539, doi:10.3762/bjoc.17.47

• occurs to give 3-methoxy-2-oxoindolin-3-yl acetate. Other reducing agents recommended in the literature for the reduction of unprotected isatin (sodium dithionite, zinc, phosphinic acid, etc.) also failed or caused an acetyl group removal. Therefore, we abandoned this strategy. Configuration of products

Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

• Sergey V. Norkov,
• Anton V. Cherkasov,
• Andrey S. Shavyrin,
• Maxim V. Arsenyev,
• Viacheslav A. Kuropatov and
• Vladimir K. Cherkasov

Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26

• reduction with sodium dithionite in a water/methanol mixture: at these conditions o-quinone 6a converts into catechol 10. It has been shown also that the thiocarbonyl group in 6a could be easily converted into a carbonyl group by action of mercury(II) acetate in solution (Scheme 3). EPR spectroscopy studies

The biomimetic synthesis of balsaminone A and ellagic acid via oxidative dimerization

• Sharna-kay Daley and
• Nadale Downer-Riley

Beilstein J. Org. Chem. 2020, 16, 2026–2031, doi:10.3762/bjoc.16.169

• photolytic cyclization of binaphthyl 16 using a 100 W bulb was attempted without success, due to degradation of the starting material. This led to a different approach employing a reductive, base-mediated cyclization using alkaline aqueous sodium dithionite. Interestingly, the typical conditions for

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• oxygen of air (Scheme 36) [126]. The peroxide initially formed in the reaction was reduced by treatment with a saturated Na2S2O4 solution. The formation of peroxide was confirmed by a control experiment in which the hydroperoxide 113b’ was isolated when the treatment of the reaction mixture with sodium

• dithionite was omitted. High yields were reached for both monosubstituted (products 113a,d,f,h) and disubstituted C=C bonds (products 113b,c,e,g). Aliphatic oximes also undergo this transformation in high yields (products 113c,g,h). The photocatalytic oxidative cyclization of β,γ-unsaturated oximes 114 was

An efficient and concise access to 2-amino-4H-benzothiopyran-4-one derivatives

• Peng Li,
• Yongqi Wu,
• Tingting Zhang,
• Chen Ma,
• Ziyun Lin,
• Gang Li and
• Haihong Huang

Beilstein J. Org. Chem. 2019, 15, 703–709, doi:10.3762/bjoc.15.65

• ) [6][7], or through the reduction of 2-nitrobenzothiopyranones with sodium dithionite (method B, Scheme 1) [8]. Apparently, synthetic methods to afford N-substituted 2-aminobenzothiopyranones are less well developed. The first example of an interchange of a 2-methylthio substituent for a nitrogen

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

• reducing reagent, the solvent used for the reaction and the reaction temperature. Sodium borohydride (NaBH4) and sodium dithionite (Na2S2O4) are the most studied reducing agents for the reduction of N-substituted pyridinium derivatives. Unlike Na2S2O4 which reduces NAD+ regioselectively to 1,4

Mild and selective reduction of aldehydes utilising sodium dithionite under flow conditions

• Nicole C. Neyt and
• Darren L. Riley

Beilstein J. Org. Chem. 2018, 14, 1529–1536, doi:10.3762/bjoc.14.129

• conditions using sodium dithionite. We now report the expansion of this method to include the reduction of aldehydes. The method developed affords yields which are comparable to those under batch conditions, has a reduced reaction time and improved space-time productivity. Furthermore, the approach allows

• the selective reduction of aldehydes in the presence of ketones and has been demonstrated as a continuous process. Keywords: aldehyde reduction; flow chemistry; selective reduction; sodium dithionite; Introduction Flow chemistry and continuous processing has been acknowledged by the American

• antipsychotic drug clozapine in which we demonstrated a flow-based reduction of a nitro group utilising sodium dithionite as a reductant [14]. We further hypothesized that the development of a flow protocol for the reduction of carbonyl groups would also be possible using sodium dithionite (Scheme 1) [15][16

Synthesis of a sucrose-based macrocycle with unsymmetrical monosaccharides "arms"

• Karolina Tiara,
• Mykhaylo A. Potopnyk and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2018, 14, 634–641, doi:10.3762/bjoc.14.50

• to 16 (in 60% yield). Both nitro compounds 14 and 16 were reduced to the corresponding amines 17 and 18 with sodium dithionite (Scheme 3). The synthesis of the macrocycle with different arms at both terminal positions was initiated from 6’-O-tert-butyldiphenylsilyl-1’,2,3,3’,4,4’-hexa-O-benzylsucrose

Membrane properties of hydroxycholesterols related to the brain cholesterol metabolism

• Malte Hilsch,
• Ivan Haralampiev,
• Peter Müller,
• Daniel Huster and
• Holger A. Scheidt

Beilstein J. Org. Chem. 2017, 13, 720–727, doi:10.3762/bjoc.13.71

• μM LUVs was recorded in a cuvette at 540 nm (λex = 470 nm, slit width for excitation and emission 4 nm) at 37 °C using an Aminco Bowman Series 2 spectrofluorometer (Urbana, IL). After 30 s, sodium dithionite was added from a 1 M stock solution in 100 mM Tris (pH 10.0) to give a final concentration of

Biochemical and structural characterisation of the second oxidative crosslinking step during the biosynthesis of the glycopeptide antibiotic A47934

• Veronika Ulrich,
• Clara Brieke and
• Max J. Cryle

Beilstein J. Org. Chem. 2016, 12, 2849–2864, doi:10.3762/bjoc.12.284

• of sodium dithionite led to conversion of ferric to ferrous heme, which was accompanied by shift of the Soret maximum to λ = 422 nm and of the β/α bands to λ = 532 and 559 nm in the UV–visible spectrum. Upon saturation of ferrous StaF with carbon monoxide, two major peaks appeared at λ = 420 and 450

Synthesis and reactivity of aliphatic sulfur pentafluorides from substituted (pentafluorosulfanyl)benzenes

• Norbert Vida,
• Jiří Václavík and
• Petr Beier

Beilstein J. Org. Chem. 2016, 12, 110–116, doi:10.3762/bjoc.12.12

• substituents ortho to the SF5 group are relatively uncommon [21]. Reduction with sodium dithionite [20] provided aminophenol 14 in good overall yield and oxidation with MnO2 [22] gave benzoquinone 12 also in a good yield. Further oxidation with H2O2/H2SO4 resulted in a mixture of four SF5-containing products

Syntheses of 2-substituted 1-amino-4-bromoanthraquinones (bromaminic acid analogues) – precursors for dyes and drugs

• Enas M. Malik,
• Younis Baqi and
• Christa E. Müller

Beilstein J. Org. Chem. 2015, 11, 2326–2333, doi:10.3762/bjoc.11.253

• synthesized compounds are important intermediates for the production of AQ dyes and for the development of potent and selective ligands for a variety of (potential) therapeutic targets. Results and Discussion Following a published procedure, 1-aminoanthraquinone (3) was treated with sodium dithionite and

• -hydroxymethylanthraquinone (6) in high yield (Scheme 2 and Table 1). The synthesis of compound 6 had previously been described in the literature by treating bromaminic acid sodium salt (2) with sodium dithionite and formaldehyde under alkaline conditions [61]. We initially tried to reproduce the published procedure, however

Syntheses of fluorooxindole and 2-fluoro-2-arylacetic acid derivatives from diethyl 2-fluoromalonate ester

• Antal Harsanyi,
• Graham Sandford,
• Dmitri S. Yufit and
• Judith A.K. Howard

Beilstein J. Org. Chem. 2014, 10, 1213–1219, doi:10.3762/bjoc.10.119

• in hand, we attempted the reduction of the nitro group in 4a using sodium dithionite, adapting reaction conditions similar to those described in the literature for the synthesis of biologically active system MaxiPost [63]. However, very low isolated yields of the cyclised product were obtained

• competing decarboxylation, rather than esterification, reflects the greater stabilisation of the carbanion system formed upon decarboxylation for this system. Reductive cyclization of methyl esters 6a–e using sodium dithionite provided fluorooxindoles 8a–e in acceptable yield after isolation by column

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• ][31][32], the trifluoromethylthio anion [29] or electrophilic perfluoroalkylating agents [33]. Others are devoted to particular methods such as trifluoromethylation initiated by sodium dithionite [34] or the electrochemical introduction of fluoroalkyl groups in organic molecules [35]. Moreover, many